Functional sodium chloride compositions

ABSTRACT

Novel functional sodium chloride compositions containing sodium gluconate as a substitute for the conventionally employed sodium chloride and being efficacious in preventing hypertension and the onset of complications thereof in the brain, heart, kidney; etc. These compositions are prepared by adding 40 to 400 parts by weight of sodium gluconate to 100 parts by weight of compositions containing 40 to 60% by weight of sodium chloride and 60 to 40% by weight of potassium chloride. These compositions are usable as a table salt for seasoning foods or in imparting the required saltiness to foods such as crackers or snacks. They are particularly appropriate for those who should cut down on the amount of salt in the diet.

TECHNICAL FIELD

This invention relates to a novel functional sodium chloride compositioncontaining sodium gluconate, which is effective in preventinghypertension or onset of cerebral, cardiac, and renal complications ofhypertension, as a substitute for salt (sodium chloride or NaCl). Thiscomposition is particularly suitable for use as a table salt forimparting saltiness to dishes or as an ingredient in food productsrequiring a salty taste, such as crackers and snack foods, particularlyfor persons in whom salt-restricted diets are indicated.

BACKGROUND ART

It is well known that the age-associated elevation of blood pressure ispromoted by sodium chloride loading and, therefore, cutting on theintake of sodium chloride is generally recommended. Moreover, for theprevention of hypertension and renal diseases arising from an excessiveintake of sodium chloride, salt-reduced foods and functional dietarysalts prepared by partial substitution of potassium for sodium have beendeveloped. However, reducing the amount of sodium chloride results inflat tastes while the use of the potassium salt leads to prominence ofthe bitter taste characteristic of potassium chloride. Thus, inwhichever of the cases, organoleptic drawbacks are inevitable. Theeating habit of the Japanese is centered around the favor of saltinessbut in order that one may lead a healthy dietary life, there must beavailable salt compositions capable of providing saltiness in degreescomparable to that of sodium chloride without affecting one's bloodpressure. Here is the problem that must be solved.

Regarding the use of salts of organic acids in lieu of sodium chloride,there is a report on the use of citric acid (Japanese Kokai Tokkyo KohoH6-189709). It is claimed, there, that hypertension can be prevented orcured by substituting potassium chloride for part of sodium chlorideand, for masking the bitterness of potassium chloride, adding a citrate,particularly tripotassium citrate. However, the saltiness attained isnot quality-wise equivalent to that of sodium chloride.

DISCLOSURE OF THE INVENTION

The inventors of this invention did an intensive exploration for asolution to the problem that there was not an agent providing forsaltiness quality-wise equivalent to that of sodium chloride withoutinducing elevation of blood pressure and arrived at sodium gluconatewhich, among various salts of sodium, has little effect on bloodpressure. The inventors then created a functional sodium chloridecomposition equivalent to sodium chloride taste-wise by adding sodiumgluconate to the conventional potassium salt composition (a mixture ofsodium chloride and potassium chloride) and have ultimately developedthis instant invention.

This invention, therefore, is concerned with a performance (functional)salt composition available upon blending of about 40-400 parts by weight(preferably about 50-100 parts by weight) of sodium gluconate with 100parts by weight of a mixture of about 40-60 weight % of sodium chlorideand about 60-40 weight % of potassium chloride.

This invention provides a novel functional dietary salt compositiontaking the pace of the conventional agent sodium chloride and useful forpreventing hypertension or onset of cerebral, cardiac and renalcomplications of hypertension. The composition may find application as asubstitute table salt for imparting saltiness to dishes or as aningredient in crackers, snack foods and other food products requiringsaltiness.

The functional sodium chloride composition of the invention which, asaforesaid, is a composition available upon blending of about 40-400parts by weight of sodium gluconate with 100 parts by weight of amixture salt consisting of about 40-60 weight % of sodium chloride andabout 60-40 weight % of potassium chloride has a salty taste of the samequality as that of sodium chloride and is characterized in that itscarcely contributes to age-related elevation of blood pressure andinhibits onset of apoplexy.

In the functional sodium chloride composition of the invention, theweight ratio of sodium chloride to potassium chloride should be withinthe range of 60:40 through 40:60. When potassium chloride is used inexcess of 60 weight %, the bitterness of potassium chloride can hardlybe masked. When the proportion of potassium chloride is smaller than 40weight %, the sodium-sparing effect is limited. A mixture of sodiumchloride and potassium chloride presents a characteristic bitter tastebut this bitterness can be masked by adding sodium gluconate. However,when the level of addition of sodium gluconate is below 40 parts byweight relative to 100 parts by weight of said mixture, the bitternesscannot be effectively masked. On the other hand, when the level ofaddition exceeds 400 parts by weight on the same basis, the necessarysaltiness is not fully developed.

It is also possible to add magnesium chloride to the above ternarymixture of sodium gluconate, potassium chloride and sodium chloride. Inthis case, the preferred level of magnesium chloride is 1 about 100parts by weight relative to 100 parts by weight of said ternary mixture.

Furthermore, the functional sodium chloride composition of the inventionmay contain one or more other components than sodium gluconate,potassium chloride, sodium chloride and magnesium chloride in a suitableproportion.

In the present invention, the mode of blending the components is notcritical but the per se known methods can be employed.

For demonstrating the usefulness of the functional sodium chloridecomposition of the invention, tests for comparative evaluation ofsaltiness and other functional qualities were performed using samples ofthe composition. The results are presented below.

TEST EXAMPLE 1 Saltiness Comparison Test

The concentration of a sodium gluconate (40 weight %)—sodium chloride(35 weight %)—potassium chloride (25 weight %) premix in water which wasequivalent to 2 weight % aqueous sodium chloride solution in saltinesswas explored. In the following description, sodium gluconate issometimes indicated by the symbol GNA, sodium chloride by NaCl, andpotassium chloride by KCl.

Aqueous solutions of the above premix as prepared to variousconcentrations and 2 weight % aqueous sodium chloride solution werecompared for saltiness in a sensory evaluation system. The results areshown in Table 1.

TABLE 1 Concentration 2.0 2.2 2.4 3.0 of premix (wt. %) Degree of WeakWeak Slightly Substan- saltiness weak tially equivalent

TEST EXAMPLE 2

Saltiness Comparison Test Using the Functional Sodium ChlorideComposition of the Invention and Sodium Chloride

A 3 weight % aqueous solution of the GNA (35 wt. %)—NaCl (35 wt. %)—KCl(30wt. %) premix and 2 weight % aqueous NaCl solution were compared in a3-sample discrimination test (triangle test).

Each panelist was given 3 cups containing the test solutions, one ofwhich contained a different solution with the remaining two cupscontaining one and the same solution and instructed to select one with adifferent taste. The test was performed twice changing the combination.As a result, the selection may be 11 of 30 panelists was correct andthis result was not statistically significant. Thus, no difference wasfound between the two solutions.

TEST EXAMPLE 3

A Saltiness Comparison Test Using the Functional Sodium ChlorideComposition of the Invention as Further Supplemented with MagnesiumChloride and Sodium Chloride

The 3 weight % aqueous solution of the composition obtained in Example 2and the 2 weight % aqueous solution of sodium chloride, which were equalin saltiness, were evaluated by the 3- sample discrimination method(triangle test). As a result, the correct discrimination was made byonly 15 out of 30 panelists.

TEST EXAMPLE 4

Bitterness Ameliorating Effect Comparison Test

The degree of bitterness amelioration which was obtained by addingsodium gluconate (GNA) to a sodium chloride (NaCl)—potassium chloride(KCl) composition was evaluated by a sensory test.

Sensory Test Protocol

The following three solutions equated in the intensity of saltiness, X,Y, and Z, were used in combinations of two each and the first-tastedsample (A) and the second-tested sample (B) were compared and scored onthe following scale. The panel consisted of 10 tasters.

Salt Solutions

X: 3 wt. % NaCl/water

Y: 1.8 wt. % NaCl+1.8 wt. % KCl/water

Z: 1.4 wt. % NaCl+1.4 wt. % KCl+1.4 wt. % GNA/water

Scoring Scale

+3: A is considerably bitterer than B

+2: A is moderately bitterer than B

+1: A is slightly bitterer than B

0: equivocal

−1: B is slightly bitterer than A

−2: B is moderately bitterer than A

−3: B is considerably bitterer than A

TABLE 2 Total Mean Before After +3 +2 +1 0 −1 −2 −3 score score X Y 0 02 0 3 1 4 −15 −1.5 Y X 3 3 2 0 2 0 0 +15 +1.5 X Z 0 2 0 2 3 2 1  −6 −0.6Z X 2 3 2 2 0 1 0 +12 +1.2 Y Z 2 5 2 1 0 0 0 +18 +1.8 Z Y 0 1 1 1 1 4 2−13 −1.3 Total 7 14  9 6 9 8 7

Analysis of variance of the above data revealed that the intensity ofbitterness was in the order of NaCl+KCl (Y), NaCl+KCl+GNA (Z), and NaClalone (X) and a significant difference was found between X and Y andbetween Y and Z but no significant difference was found between X and Z.It was, therefore, clear that addition of GNA masked the bitterness ofKCl.

The relationship of the intensities of bitterness of X, Y, and Z isdiagrammatically illustrated in FIG. 1.

TABLE 3

Then, a comparative test was performed for demonstrating the usefulnessof sodium gluconate which is a main component of the functional sodiumchloride composition of the invention.

TEST EXAMPLE 5

Effect on Blood Pressure in Hypertensive Rats

(1) Method

Male spontaneously hypertensive rates (SHR) purchased from Japan SLC atthe age of 4 weeks were preliminarily fed with the commercial food CE-2Powder (Clea Japan) for 1 week and submitted to the experiment at theage of 5 weeks. Using stainless steel suspension breeding cages, 4 SHRswere housed per cage. Before commencement of the experiment, the ratswere divided into groups of 8 in such a manner that their group meanbody weights would be equal. To the commercial powdery low-salt food(Clea Japan, Na concentration 11.3 mg/100 g), the test compositions wererespectively added as shown in Table 4 and the animals were allowed freeaccess to the diets (Na concentration 0.527 weight %) and water (tapwater containing 2 ppm of chlorine). The blood pressure and body weightwere determined at commencement of feeding and thereafter at intervalsof 2˜3 weeks. The animal room was controlled at 23±1° C. and 55±5% RH,with a 12-hr lighting cycle (ON 8:00˜20:00, OFF 20:00˜8:00). To generateblood pressure data, the systolic blood pressure of the tail artery ofrats was measured with Muromachi Machinery's MK1000.

TABLE 4 Level of addition of test compositions 1˜3 (weight %) Corn NaClGNA MNA starch Composition 1 1.34 0.00 0.00 3.66 Composition 2 0.00 5.000.00 0.00

As the basal diet, the powdery low-salt food from Clea Japan was used.The Na concentration of the prepared diets was 0.527 weight %.

In the table, GNA stands for sodium gluconate

(2) Results

At week 3 of the experiment, a difference in blood pressure began toappear between the GNA (Composition 2)-fed group and the NaCl(Composition 1)-fed group and the blood pressure in the GNA (Composition2) group being significantly lower consistently till week 11. There wasno difference in body weight between the groups. The data are shown inTable 5.

TABLE 5 The time course of systolic blood pressure in SHR Week 0 3 5 7 911 13 Blood Composi- 155± 197 ± 230 ± 247 ± 254 ± 254 ± 276 ± pres- tion1 11.6 11.9 16.6 15.9 16.3 16.0 20.7 sure group Composi- 157 ± 189 ± 207± 225 ± 230 ± 231 ± 250 ± tion 2 10.1 15.9 10.6 12.6 7.6 16.7 12.9 groupANOVA Composi- NS 0.05 0.005 0.01 0.005 0.01 0.01 tion 1 to Composi-tion 2 Body Composi- 117 ± 243 ± 281 ± 312 ± 331 ± 349 ± 363 ± weighttion 1 5.0 10.6 10.4 12.9 12.5 12.6 17.2 group Composi- 117 ± 239 ± 279± 310 ± 331 ± 349 ± 362 ± tion 2 6.6 12.9 10.0 10.2 10.8 10.5 10.0 groupANOVA: analysis of variance

TEST EXAMPLE 6 Effect on the Heart and Kidney in SHR

(1) Method

When the rats used in the above experiment on the effect on bloodpressure reached the age of 20 weeks, their body weights weredetermined. The animals were then suffocated to death with dry ice andthe heart and kidney were isolated and weighed to record wet weights.The respective organ weights were adjusted for body weight andtabulated.

(2) Results

The test results are presented in Table 6. The heart weight and kidneyweight in the GNA (Composition 2)-fed group were significantly low. Theanimals in the NaCl (Composition 1)-fed group developed hypertrophy ofthe heart and kidney due to the marked NaCl loading on the heart andkidney, thus accounting for the significant differences in heart weightand kidney weight. The results indicated that GNA is useful for theprevention of hypertension-associated renal failure and cardiomegaly.

TABLE 6 The heart and kidney weights (g) of SHR at week 20 of feeding (n= 8, mean ± standard deviation) Organ weights per kg body weight BodyHeart Kidney Heart Kidney weight weight weight weight weight Composition1 390 ± 1.8 ± 3.5 ± 4.6 ± 8.9 ± group 18.3 0.11 0.19 0.29 0.38Composition 2 397 ± 1.7 ± 3.3 ± 4.2 ± 8.3 ± group 12.5 0.08 0.15 0.15*0.22** *0.5% level of significance **1% level of significance

TEST EXAMPLE 7 Effect on Apoplexy (Life Span) in Apoplectic Rats

(1) Method

Male SHRSP/Izm (briefly, SHRSP) rats purchased from Funabashi Farm werefed in the same manner as the SHRs used in the experiment on the effectof blood pressure and were monitored until death. Unlike the rats usedin the blood pressure experiment, those rats were divided into groups of10˜11 and housed 3˜4 individuals per cage.

(2) Results

The results are presented in Table 7. A significant difference was foundin the number of survival days between the Composition 2-fed group andthe Composition 1-fed group. The mean life span was 359±71.9 days in theComposition 2 group versus 222±58.8 days in the Composition 1 group.Analysis by the Kaplan-Meier method revealed a significant intergroupdifference at the 0.05% level of significance. Because of theirinherited character, SHRSPs die of apoplexy without living through theaverage life span of rats.

TABLE 7 Cumulative survival curve (Kaplan-Meier method)

The results of the above experiments indicated that the functionalsodium chloride composition containing sodium gluconate according to theinvention is equivalent to sodium chloride in saltiness. Moreover, astested in spontaneously hypertensive rats, the functional sodiumchloride composition of the invention as a feed supplement tends toinhibit age-associated elevation of blood pressure as compared withsodium chloride. It is also found that the composition is useful for theprophylaxis of hypertension associated renal failure and cardiomegaly.Furthermore, as tested in the SHRSP, the functional sodium chloridecomposition of the invention acts in an inhibitory way on apoplexy toprolong the life span of rats.

The above results indicate that the functional sodium chloridecomposition available upon blending of 40˜400 parts by weight of sodiumgluconate with 100 parts by weight of a mixture of 40˜60 weight % ofsodium chloride and 60˜40 weight % of potassium chloride is equivalentto sodium chloride in saltiness, scarcely contributory to age-associatedelevation of blood pressure, and inhibitory against onset of apoplexy.

The following examples are further illustrative of the invention but byno means limitative of the scope of the invention.

EXAMPLE 1

A functional sodium chloride composition (100 g) was obtained byblending 35 g of sodium gluconate with 35 g of sodium chloride and 30 gof potassium chloride.

EXAMPLE 2

A functional sodium chloride composition (102 g) was obtained byblending 2 g of magnesium chloride with 100 g of the compositionobtained in Example 1.

What is claimed is:
 1. A sodium chloride replacement compositionavailable upon blending of 40˜400 parts by weight of sodium gluconate to100 parts by weight of a mixture of 40˜60 weight % of sodium chlorideand 60˜40 weight % of potassium chloride.
 2. A sodium chloridereplacement composition available upon blending 1˜10 parts by weight ofmagnesium chloride with 100 parts by weight of the sodium chloridereplacement composition defined in claim
 1. 3. A method of preventinghypertension or onset of cerebral, cardiac and renal complications ofhypertension, comprising administering an effective amount of thecomposition of claim 1 to a human in need thereof.
 4. A method ofpreventing hypertension or onset of cerebral, cardiac and renalcomplications of hypertension, comprising administering an effectiveamount of the composition of claim 2 to a human in need thereof.